Electric motors are a common source of mechanical power, being used in a wide variety of applications and devices, such as electric fans, washing machines, water pumps etc. Generally, a motor is composed of two parts, namely a rotor and a stator. A one type of motor, the stator is composed of a magnetic core with windings wound around the magnetic core. The rotor may have a permanent magnet. When energized, the windings of the stator generate a magnetic field which interacts with a magnetic field of the rotor to rotate the rotor and in turn drive a load.
The magnetic core of a known wound stator is generally formed by stacking a large number of silicon steel sheets or laminations. Each silicon steel sheet is formed by directly punching a thin sheet material. Each silicon steel sheet comprises an annular yoke, and teeth radiating from the yoke part. For a stator used in an outer rotor motor, the teeth radiate outwardly from the yoke. An annular supporting part is formed at a central area of the yoke. The supporting part is used to fixedly connect the stator to other components. The windings are wound around the teeth. Although the manufacturing procedure of the stator core of the existing stator is simple, the punching process use to form the stator laminations generates a large amount of waste material, resulting in a high cost.